CO2 sensor and method for manufacturing same

Abstract

A sensor device for sensing CO2 comprises a hybrid sensing material and a transducer. The hybrid sensing material comprises at least amines and nanoparticles, wherein the hybrid sensing material has a property and is configured to change the property dependent on a current CO2 concentration in the surrounding. The transducer is configured to output an electrical sensor signal dependent on the property of the hybrid sensing material.

The invention claimed is: 
     
       1. A sensor device for sensing CO 2 , comprising:
 a hybrid sensing material comprising a mixture of at least amines and nanoparticles, wherein the hybrid sensing material comprises an electrical or optical property and is configured to change the electrical or optical property dependent on a CO 2  concentration in the surrounding; and 
 a transducer configured to output an electrical sensor signal dependent on the electrical or optical property of the hybrid sensing material, the property is an electrical or optical property out of a group comprising impedance, capacitance and optical transmission. 
 
     
     
       2. The sensor device according to  claim 1 , wherein the transducer comprises two electrodes, wherein at least one electrode is coupled to the hybrid sensing material in order to detect the electrical or optical property of the hybrid material. 
     
     
       3. The sensor device according to  claim 2 , wherein the hybrid sensing material is arranged between the two electrodes and/or is arranged on top of said at least one electrode. 
     
     
       4. The sensor device according to  claim 2 , wherein the electrodes comprise any conducting material or a metal or a conducting polymeric material, or a metal selected from the group of Ni, Au, Ag, Pt, or combinations thereof. 
     
     
       5. The sensor device according to  claim 1 , wherein the transducer comprises a field effect transistor with a pair of source/drain regions, a channel and a suspended gate electrode, wherein the hybrid sensing material is positioned between the channel and the suspended gate electrode. 
     
     
       6. The sensor device according to  claim 1 , wherein in transducer comprises an upper electrode, a lower electrode and a quartz plate positioned between the upper and lower electrodes, wherein the hybrid sensing material is positioned on the upper electrode. 
     
     
       7. The sensor device according to  claim 1 , wherein the transducer comprises a piezoelectric substrate, a first pair of interdigitated electrodes, a second pair of interdigitated electrodes on said piezoelectric substrate, wherein the first pair of interdigitated electrodes is connected to a voltage source, and wherein the hybrid sensing material is positioned on the piezoelectric substrate between the first and second pairs of interdigitated electrodes. 
     
     
       8. The sensor device according to  claim 1 , wherein the transducer comprises a light emitting device, a light receiving device, wherein the hybrid sensing material is positioned between the light receiving device and the light emitting device so that the light beam emitted by the light emitting device propagates through the hybrid sensing material and is received by the light receiving device. 
     
     
       9. The sensor device according to  claim 1 , further comprising a heater for heating the hybrid sensing material. 
     
     
       10. The sensor device according to  claim 1 , wherein the hybrid sensing material reacts with CO 2  in accordance with the formula 
       
         
           
             
               
                 RNH 
                 2 
               
               + 
               
                 
                   
                     CO 
                     2 
                   
                   ⁢ 
                   
                     ⟶ 
                     
                       
                         + 
                         
                           H 
                           2 
                         
                       
                       ⁢ 
                       O 
                     
                   
                   ⁢ 
                   
                     ⟵ 
                     
                       
                         - 
                         
                           H 
                           2 
                         
                       
                       ⁢ 
                       O 
                     
                   
                   ⁢ 
                   
                     R 
                     + 
                   
                 
                 ⁢ 
                 
                   NH 
                   3 
                 
               
               + 
               
                 HCO 
                 3 
                 - 
               
               + 
               
                 RNH 
                 2 
               
             
           
         
       
       or in accordance with the formula
   2RNH 2 +CO 2 →←RNCO 2    − R+HH 3   + .
 
 
     
     
       11. The sensor device according to  claim 1 , wherein the electrical sensor signal is indicative for a measured impedance or capacitance; wherein an increase of the CO 2  concentration leads to a change of the impedance or capacitance. 
     
     
       12. The sensor device according to  claim 1 , wherein the electrical sensor signal is dependent on the CO 2  concentration in the surrounding and on the relative humidity in the surrounding. 
     
     
       13. The sensor device according to  claim 1 , wherein the hybrid sensing material comprises organic and inorganic compounds. 
     
     
       14. The sensor device according to  claim 1 , wherein the hybrid sensing material comprises a polymer or polymer-based amines. 
     
     
       15. The sensor device according to  claim 1 , wherein the amines are out of a group comprising primary amino groups and secondary amino groups. 
     
     
       16. The sensor device according to  claim 1 , wherein the amines are out of a group comprising: 3-aminopropyltrimethosysilane; APTMS; 3-Aminopro(pyl)triethoxysilane; APTES; Polypropyleneimine; PPI; mono(di)ethanolamine MEA; DEA; Polyethyleneimine; PEI; 2-diethylamino-ethanol; DEEA; 1,4-diaminobutane; DAB; 1,3-propanediamine; DiAP; 2,2-dimethyl-1,3-propanediamine; DMPDA; 1-piperazineethanol; HEP; 2-diisopropylamino-ethanol; DIPAE; N,N,N′,N′-tetrabutyl-3-oxapentanediamide; N-TBDA; N1-methyl-1,3-Propanediamine; MAPA; and Polyallylamine; PAA. 
     
     
       17. The sensor device according to  claim 16 , wherein the electrical or optical property change as response to a CO 2  concentration differs from the electrical or optical property change as response to a H 2 O concentration. 
     
     
       18. The method according to  claim 17 , wherein providing the hybrid sensing material is performed using coating or drop in, coating, spray coating, dip coating, doctor blade on the transducer or on a substrate comprising the transducer. 
     
     
       19. The sensor device according to  claim 1 , wherein the hybrid sensing material is configured to change the electrical or optical property dependent on a H 2 O concentration in the surrounding. 
     
     
       20. A method for manufacturing a sensor device for sensing CO 2 , comprising:
 providing a transducer configured to output an electrical sensor signal dependent on a electrical or optical property of a hybrid sensing material; and 
 providing the hybrid sensing material comprising at least amines and nanoparticles, wherein the hybrid sensing material comprises an electrical or optical property and is configured to change the electrical or optical property dependent on a CO 2  concentration in the surrounding, where the property is an electrical or optical property out of a group comprising impedance, capacitance and optical transmission; 
 further comprising dispersing the amines and the nanoparticles or polymer-amines and the nanoparticles by usage of a solvent before providing the hybrid sensing material; wherein dispersing is performed using mixing the solvent under stirring. 
 
     
     
       21. The method according to  claim 20 , further comprising drying the solvent after providing the hybrid sensing material. 
     
     
       22. A coating comprising a hybrid sensing material for sensing CO 2  comprising a mixture of at least amines and nanoparticles, wherein the hybrid sensing material comprises an electrical or optical property and is configured to change the electrical or optical property dependent on a CO 2  concentration in the surrounding, wherein the nanoparticles comprise one material out of the group comprising SiO 2 , Al 2 O 3 , TiO 2 , ZrO 2 , and combinations thereof. 
     
     
       23. A sensor device for sensing CO 2 , comprising:
 a hybrid sensing material comprising a mixture of at least amines and nanoparticles, wherein the hybrid sensing material comprises an electrical or optical property and is configured to change the electrical or optical property dependent on a CO 2  concentration in the surrounding; and 
 a transducer configured to output an electrical sensor signal dependent on the electrical or optical property of the hybrid sensing material; 
 wherein in transducer comprises an upper electrode, a lower electrode and a quartz plate positioned between the upper and lower electrodes, wherein the hybrid sensing material is positioned on the upper electrode; or 
 wherein the transducer comprises a piezoelectric substrate, a first pair of interdigitated electrodes, a second pair of interdigitated electrodes on said piezoelectric substrate, wherein the first pair of interdigitated electrodes is connected to a voltage source, and wherein the hybrid sensing material is positioned on the piezoelectric substrate between the first and second pairs of interdigitated electrodes; or 
 wherein the transducer comprises a light emitting device, a light receiving device, wherein the hybrid sensing material is positioned between the light receiving device and the light emitting device so that the light beam emitted by the light emitting device propagates through the hybrid sensing material and is received by the light receiving device. 
 
     
     
       24. A sensor device for sensing CO 2 , comprising:
 a hybrid sensing material comprising a mixture of at least amines and nanoparticles, wherein the hybrid sensing material comprises an electrical or optical property and is configured to change the electrical or optical property dependent on a CO 2  concentration in the surrounding; and 
 a transducer configured to output an electrical sensor signal dependent on the electrical or optical property of the hybrid sensing material; 
 further comprising a heater for heating the hybrid sensing material. 
 
     
     
       25. A sensor device for sensing CO 2 , comprising:
 a hybrid sensing material comprising a mixture of at least amines and nanoparticles, wherein the hybrid sensing material comprises an electrical or optical property and is configured to change the electrical or optical property dependent on a CO 2  concentration in the surrounding; and 
 a transducer configured to output an electrical sensor signal dependent on the electrical or optical property of the hybrid sensing material; 
 wherein the electrical sensor signal is dependent on the CO 2  concentration in the surrounding and on the relative humidity in the surrounding; or 
 wherein the hybrid sensing material is configured to change the electrical or optical property dependent on a H 2 O concentration in the surrounding, where the property is an electrical or optical property out of a group comprising impedance, capacitance and optical transmission; or 
 wherein the electrical or optical property change as response to a CO 2  concentration differs from the electrical or optical property change as response to a H 2 O concentration, where the property is an electrical or optical property out of a group comprising impedance, capacitance and optical transmission. 
 
     
     
       26. A sensor device for sensing CO 2 , comprising:
 a hybrid sensing material comprising a mixture of at least amines and nanoparticles, wherein the nanoparticles comprise one material out of the group comprising SiO 2 , Al 2 O 3 , TiO 2 , ZrO 2 , and combinations thereof; 
 wherein the hybrid sensing material comprises an electrical or optical property and is configured to change the electrical or optical property dependent on a CO 2  concentration in the surrounding; and 
 a transducer configured to output an electrical sensor signal dependent on the electrical or optical property of the hybrid sensing material.